ou are a logician in training for the police, and the time has come to take the certification test. The police chief brings you the test one morning, and says, "I must warn you, this is your only chance at the certification test; If you fail, you must keep training for another year before you can take it again."

- Five suspects were interrogated for a bank robbery.

- Each suspect was either a knight, a knave, or a liar.

- Knights always tell the truth.

- Liars always lie.

- Knaves strictly alternate truths and lies with each statement.

- Police have evidence that suggests the perpetrator acted alone.

- Police have evidence that suggests the perpetrator acted alone.

>During the interrogation, two questions were asked (consecutively) of each of the five suspects. Each suspect heard the other suspects' responses, and none of them made a statement between his or her two answers. Here are the two questions and their responses.

"Did you rob the bank?"
A: No.
B: No.
C: No.
D: Yes.
E: Yes.

"Who robbed the bank?"
A: E.
B: A.
C: l don't know.
D: E.
E: A.

The interrogators mentioned that something about their statements didn't seem quite right. The police chief adds, "The only hints I can give you are that C is not a knight and that there is only one correct answer. I'll be back in 24 hours to ask you who robbed the bank."

Since there was '"suggested... acting alone", then any answer by any
suspect that identifed another as the perp might be considered a
lie. Therefore, A, B, D, E all lied on the second question.
If one then assumes that C must be telling the truth whne he says "I
don't know", then C must be a Knight if A, B, D, or E is the assumed
guilty party - not allowed. Therefore, the only answer that works
is C, and the "something not quite right" is that any susepect giving
an answer to the second question that names another is fishy.